The present disclosure relates to a switchgear, and more particularly, to a switchgear from which an arc is discharged.
In general, a switchgear is electric equipment for safely supplying industrial power to the user. In the switchgear, devices such as a current transformer, a power transformer, a circuit breaker, and the like are safely accommodated in an iron enclosure.
FIG. 1 is a side view illustrating the inside of a switchgear according to the related art, and FIG. 2 is a perspective view of the switchgear according to the related art.
As illustrated in FIG. 1, a switchgear according to the related art, particularly, a metal-clad switchgear (MCSG) may be divided into a plurality of compartments. Also, a relay current transformer, a circuit breaker, a cable, a main busbar, and the like may be accommodated in the compartments, respectively. For example, the switchgear may include a current transformer compartment 2 in which a relay current transformer 2A is accommodated, a circuit breaker compartment 8 in which a circuit breaker (not shown) is accommodated, a relay compartment 9 in which a relay for controlling the switchgear is disposed, a cable compartment 1 in which a cable (not shown) is accommodated, and a main busbar compartment 3 in which a main busbar is accommodated.
Particularly, the current transformer compartment 2 may be partitioned from the cable compartment 1 by a lower partition wall 5 and be partitioned from the main busbar compartment 3 by an upper partition wall 6.
An arc may be generated in the switchgear due to a short-circuit accident, and the arc may be quickly discharged to the outside of the switchgear through an arc duct 7. For example, an arc generated in the circuit breaker compartment 8 or the relay compartment 9 may be discharged through a front arc duct 7A, and an arc generated in the main busbar compartment 3 may be discharged through at least one of the front arc duct 7A and a rear arc duct 7B.
Particularly, when an arc is generated in the cable compartment 1, the arc may not be introduced into the current transformer compartment 2 by the lower partition wall 5 but be discharged to the arc duct 7B through an arc passage 4 disposed at a rear side of the current transformer compartment 2.
However, the arc passage 4 may be a narrow space between the current transformer compartment 2 and a rear plate of the switchgear. Thus, the arc generated in the cable compartment 1 may not be smoothly discharged. In this case, a relatively weak portion within the switchgear may not withstand the internal pressure due to the arc and thus be broken down. As a result, when the arc leaks, there is a risk of leading to a serious accident. In addition, if the arc passage 4 is widened unintentionally, the switchgear may increase in size.